Cellulosic products and method for preparing same



Patented Feb. 9, 1957 UNITED STATES CELLULOSIO PRODUCTS AND IWETHOD PREPARING SAME FOR Winfield Walter Heckert, Ardentown, Del., as-

signor, by mesne assignments, to E. I. du Pont de Nemonrs & Company, Wilmington, Del., a

corporation oi Delaware No Drawing. Application September 15, 1934, Serlal No. 744,260

- 14'Claims.

This invention relates to cellulosic structures such as filaments, threads, fabrics, sheets, films, caps, tubing, or the like. More particularly, this invention relates to cellulosic structures of the type just mentioned having a. subdued or low luster or that are more or less opaque.

This invention is in part a continuation of my copending application, Serial No. 673,315, filed May 27, 1933.

In the ordinary methods of preparing cellulosic structures, such asfilaments, threads, films, caps, tubing, etc., from viscose, cuprammonium, nitrocellulose, cellulose acetate and other cellulosic solutions (without the addition of opaquing or low luster-inducing agents to the solutions), the products are transparent or translucent or very highly lustrous. For many purposes, transparency, brilliant sheen and luster are not desirable and thus restrict the uses of the materials. Recently, various methods have been proposed for producing cellulosic structures having a low or subdued luster or opacity.

I have found that I can produce cellulosic structures characterized by a low luster or opacity by incorporating therein a heterocyclic nitrogen compound of the character described more in detail hereinafter and which imparts low luster or opacity thereto by remaining in the cellulosic structure.

duction of new opacified or low luster cellulosic structures. A further object of the invention relates to the production of novel cellulosicstructures containing organic compounds which rewashing, ironing, etc.

An object of the invention comprises the promaking and finishing the same during the manufacture thereof. They also effectively resist removal or change during any of the usual processes to which the finished cellulosic structure may be subjected,such as boiling-off, dyeing, bleaching,

These substances are incompatible with the mass of the substance constituting the final product They may be soluble, but, in the preferred embodiment of this invention, they are insoluble in the solution from which the structure is prepared.

Highly efl'ective delusterants function in particular by reason of their opacifying power which is a function of the difference in refractive index between the delusterant particle and the surrounding medium. Those in my preferred range differ from the index of the medium by at least 0.10 and the greater this difference, the more effective the compound as an opacifier or delusterant. Most organic compounds have several indexes and the statement just made refers to the highest index of the compound or to any one of the several indexes.

As illustrative examples of heterocyclic nitrogen compounds coming within the scope of this invention are the following:

2,3 diphanyl-indol N-phonyl carbazole an opaquing or a low luster-inducing agent of the type hereinafter more fully explained.

As a low luster-inducing agent, this invention contemplates the use of heterocyclic nitrogen compounds containing four or more cyclic nuclei highly deficient in hydrogen where only one nucleus is heterocy c. The invention also contemplates heterocyc ic nitrogen compounds containing two or more heterocylic nuclei.

Sofar as the instantinvention is concerned, each closed chain of carbon or heteroatoms or combination of carbon and heteroatoms will be a considered a nucleus. Thus, benzene, naphthalene and carbazolehave one, two, and three low luster-inducing agents,

Alpha-naphthoquinollne Betana hthoquim al dine Ethylene dicarbazole (dicarbazyl ethane) ms phenyl acridine Diphthalyl ethylene diimide N-alpha-nsphthyl phthalimi'de 1,4-phenylene dicarbazole 1.2,7,8-dibanzoccrldine Alpha, beta-dinapbthazine 1 Alpha, beta-diquinolyl The scope of this invention is not intended to include heterocyclic nitrogen compounds containing less than tour cyclic nuclei except where such compound contains two or more heterocyclic nuclei. 1,

Heterocyclic nitrogen compounds of the character described which have a relatively high index of refraction and are preferred on the basis of cost, color stability, acid 'insolubility and effectiveness are the following: I

Phenyl carbazole, diquinolyl, ethylene di-carbazole, ms phenyl carbazacridine, diphthalyl ethylene, diimide, N naphthyl phthalimide, phenylene di-carba zole.

The quantity of the low luster-inducing or opaquing agent which may be used, may vary within wide limits, depending principally upon the opaquing and luster desired in the final product. Cellulosic structures containing these low lusterinducing or opaquin'g agents in amounts ranging from (MO-20.0% by'weight have given satisfactory results, but, of course, it is obvious that smaller or larger quantities may be'employ'ed as desired. when a viscose solution is employed,

satisfactory results may be secured if it contains 7% cellulose and from Mil-1.5% more or less of the low luster-inducing or opaquing agent;

If desired, the low luster-inducing agents contemplated by the instant invention may be used in combinationwith each other or with other lowluster-inducing agents, such as mineral oil, petroleum jelly, waxes, paraflin, benzene, toluene, pine oil or inorganic pigments, such as titanium oxide, lithopone,zinc sulfide, etc. v

The low luster-inducing agent may be added to the solution at any stage in the course of the manufacture thereof, or after the preparation of the solution and prior to the spinning, extrusion or casting operation. It may be added directly,

sulfonated oils, alkyl naphthalene sulfonates, sodium caseinate, etc. or combinations thereof.

In order to more fully explain the principles of this invention, the following illustrative examples are given. b

Example 1.N-phenyl carbazole is ground in a colloid mill with water and with a small amount of sodium caseinate until most of the particles are below 1 micron in diameter. The slurry is diluted with water and allowed to settle overnight. Then, the supernatant liquid is drawn 01!. A sufllcient amount of this suspension is added to the cellulose xanthate and sodium hydroxide in the mixer to yield a final viscose solution containing 7% cellulose, 6% sodium hydroxide and 0.7% N-phenyl-carbazole. The -N-phenyl carbazole is thoroughly incorporated and distributed throughout the viscose during the mixing operation. The viscose is filtered, ripened and spun or cast in the usual way.

Example 2.--A suspension of finely divided phenylene di-carbazole is prepared in the man ner described in Example 1, or by any other suitable manner known to those skilled in the art.

The suspension is added to and uniformly incor- I porated in the viscose, using such amounts as to produce a solution containing 0.5% phenylene dicarbazole, 7% cellulose and 6% NaOH. The resulting viscose is processed, ripened, filtered, spun or cast and the product purified in the usual way.

Example 3.N-phenyl carbazole is ground to a particle size of from F2 microns in diameter in any suitable manner known to those skilled in the art and then suspended in a solvent mixture comprising 80% acetone and ethyl alcohol. A

sufilcient amount of this suspension is then added terfere. It has already been pointed out that the to a cellulose acetate solution containing cellulose acetate to producea thread when spun therefrom containing 5% N-phenyl carbazole.

It is to be understood that these examples do not in any way restrict the invention thereto but merely illustrate several specific and preferred embodiments which have given satisfactory results.

Though the preferred embodiments of this invention contemplate the incorporation of the low luster-inducing agent in the solution at some time prior to the extrusion or casting thereof, satisfactory results may be secured also by applying the low luster-inducing agent to a previously formed cellulosic structure. In other words, the low luster-inducing agent may be incorporated in the finalcellulosic structure by an after-treatment.

Though the invention has been specifically de-i scribed in connection with the viscose process, it is obvious that the principles thereof are equally applicable to the cuprammonium cellulose; cellulose nitrate, and cellulose acetate processes.

In the case of cellulosic solutions of wholly organic solvents, it is only necessary that a suitable;

choice of heterocyclic nitrogen compound be made so that the solubility characteristics do not in-'- low luster-inducing substances must be incompatible with the mass of substance constituting In addition, in the case of stance be insoluble in the solvent employed: However, resinous materials and certain' crystallized substances, soluble in the solvent, precipitate, upon evaporation of the solvent, in the cellulose acetate in the form of fine amorphous or crystalline particles sufilciently smalland well distributed to avoid harmful effect on the physiexcept as set forth in the claims.

aocaaoe cal properties of the resulting structure. The advantage in such cases lies in avoiding the necessity for emulsifying or grinding the compounds to obtain suitable subdivision. Suitable com pounds may be readily selected from any specific system by one skilled inthe art. While the invention has been described generally with respect to the use of the various compounds mentioned herein, in opaquing cellulosic structures prepared by casting or spinning methods, it is desired to emphasize the fact that these compounds are of special benefit in the spinning of artificial silk. Thus, undelustered artificial silk has a shade and luster which is undesired for a great many purposes. In accordance with the present invention, it is possible to produce artificial silk, particularly of the regenerated cellulose type prepared from viscose or cuprammonium cellulose, having a pleasing dull appearance, the dullness being of any degree desired, in which the opaquing or delustering agent is uniformly distributed and which does not interfere with the tenacity of the yarn to any large extent. Since it is obvious that various changes and modifications may be made in the above description without departing from the nature or spirit thereof, this invention is not restricted thereto I claim: 1. Delustered cellulosic articles prepared from cellulosic solutions containing, in.a phase distinct from that of the cellulosic material therein,

a white, finely divided delustering agent comprising a heterocyclic nitrogen compound having four or more cyclic nuclei highly deficient in hydrogen.

2. Delustered cellulosic articles prepared from cellulosic solutions containing, in a phase distinct from that of the cellulosic material therein, a white, finely divided delustering agent comprising a heterocyclic nitrogen compound having two or more heterocyclic nuclei highly deficient in hydrogen.

3. Delustered cellulosic articles prepared from cellulosic solutions containing, in aphase distinct from that of the cellulosic material therein, a white, finely divided delustering agent comprising a heterocyclic nitrogen-compound having four or more cyclic nuclei highly deficient in hydrogen and having an index of refraction differing at least 0.1 from the index of refraction of the cellulosic medium of said filaments and pellicles.

4. Delustered cellulosic articles prepared from cellulosic solutions containing, in a phase distinct from that of the cellulosic material therein, a white, finely divided delustering agent comprising a heterocyclic nitrogen compound having two or more heterocycllc nuclei highly deficient, in

hydrogen and having an index of refraction differing at least 0.1 from the index of refraction of the cellulosic medium of said filaments and pellicles.

5.- Delustered cellulosic articles prepared from cellulosic solutions containing, in a phase distinct from that of the cellulosic material therein, a white, finely divided delustering agent comprising a heterocyclic nitrogencompound having I four or more cyclic nuclei highly deficient in hydrogen taken from the group consisting of 2,3 diphenyl-indol, N-phenyl carbazole, 1,2 benzocarbazole, 2,3-benzo-carbazole, 3,4-benzo carbazole, 'dinaphtho-carbazole, phenanthro-carbazole, phenyl-bis-(a methyl-p indolyD-methane,

1-benzyl-2-phenyl-benzimidazole, 4-benzal-bis-J (1-phenyl-3 methyl-pyrazolone-5), methyleneq bistantipyrin) 4.4 benzal-bismntip'yrin) methenyl-bis(1-phenyl-3 methyl-pyrazolon-5), 2,3,5- triphenyl-pyroll, 2,3,4,5-tetraphenyl-pyroll, bipyrazol, dipyrryl methane, lW-methylene-dipyroll, benzo-methyl bis-pyrazolon, N-diphenyl piperazine, phenyl-benzyliminazole, alpha-naphthyl morpholine, dicarbazyl, alpha-naphthoquinoline, beta-naphthoquinaldine, N-benzyl carbazol, ethylene dicarbazole (dicarbazyl ethane), ms-phenyl acridine, diphthalyl ethylene diimide, N-alphanaphthyl phthalimide, 1,4-phenylene dicarbazole, 1,2,7,8-dibenzoacridine, alpha, beta-dinaphthazine, alpha, beta-diquinolyl.

6. Delustered cellulosic articles prepared from cellulosic solutions containing, in a phase distinct from that of the cellulosic material therein, a finely divided delusterlng agent, said agent com- I prising phenyl carbazole.

7. Delustered cellulosic articles prepared from cellulosic solutions containing, in a phase distinct from that ofthe cellulosic material therein, a

finely divided delustering agent, said agent comprising diquinolyl.

8. Delustered cellulosic articles prepared from cellulosic solutions containing, in a phase distinct from that of the cellulosic material therein,

.a finely divided delustering agent, said agent comprising phenylene. di-carbazole.

9. An artificial thread produced from a cellu- I losic base having an incompatible, finely divided white opa'cifying and/or low luster-inducing I agent incorporated therein, said agent comprising a heterocyclic nitrogen compound containing four or more cyclic nuclei highly deficient in hydrogen.

10. An artificial thread produced from a cellulosic base having an incompatible, finely divided white opaciiying and/or low luster-inducing agent incorporated therein, said agent comprising a heterocyclic nitrogen compound containing four or more cyclic nuclei highly deficient-in hydrogen and'having an index of refraction differing at least 0.1 from the index of refraction of the cellulosic base.

11. An artificial thread produced from a cellu losic base having an opacifying and/or low luster-inducing agent incorporated therein, said agent comprising a heterocyclic nitrogen compound having four ormore cyclic nuclei highly deficient in hydrogen, taken from the group consisting of 2,3 diphenyl-indol, N-phenyl carbazole, 1,2-benzo-carbazole, 2,3-benzo-carbazole, 3,4-benzo-carbazole', dinaphtho-carbazole, phenanthrocarbazole, phenyl-bis-(a methyl-p indolyD- methane, 1-benzy1-2-phenyl-benzimidazole, 4- benzal bis(1-phenyl-3 methyl pyrazolone 5) methylene-bis(antipyrin), 4,4 benzal-bi s(anti-, pyrin) methenyl-bis(1-phenyi-3- methyl-pyrazo- Ion-5), 2,3,5-triphenyl-pyroll, 2,3,4,5-tetraphenyl-pyroll, bipyrazol dipyrryl methane, N-meth ylene-dipyroll, benzo-methyl bis-pyrazolon, N- diphenyl piperazine, phenyl-benzyl iminazole, alpha-naphthyl morpholine, dicarbazyl, alphanaphoquinoline, beta-naphthoquinaldine, N- benzyl carbazol, ethylene dicarbazole carbazyl ethane), ms-phenyl acridine, diphthalyl ethylene phthalimide, 1,4-phen'ylene dicarbazole, dibenzoacridine, alpha, beta dinaphthazine, alpha, beta-diquinolyl.

12. An artificial thread produced from regenerated cellulose having an opacifying and/or low luster inducing agent incorporated therein, said agentcomprising phenyl carbazole.

13. .An artificial thread produced from regenerated cellulose having an opacifying and/or low luster-inducing agent incorporated therein, said agent comprising diquinolyl.

14. An artificial thread produced from regenerated cellulose having an opacifying and/or low luster-inducing agent incorporated therein, said agent comprising phenylene. di-carbazole.

' WINFIELD'WALTER HECKERT. 

